The invention relates to a process for producing packages used as feeding packages for twisting, onto which two prestrengthened yarn components are wound side-by-side as a double yarn, two yarn components, in each case, passing through a drafting unit and a false-twisting device behind the drafting unit. The two yarn components are subsequently guided together and wound onto a spool as a double yarn to form a package, and in the event of a breakage of one yarn component, the other yarn component is cut. The invention also relates to an arrangement for producing packages used as feeding packages for twisting using this process.
In a known arrangement (German Published Examined patent application Ser. No. DE-A 36 06 932), it is endeavored to have only double yarns move onto the spool to form a package. For this purpose, it is provided that, in the event of a breakage of only one yarn component, the other yarn component is cut also. Preventing that only one yarn component moves onto the spool and is wound up in the yarn package is extremely important in practice. Since the two yarn components of the double yarn, which are to be wound up side-by-side, practically have no mutual bond, the ends of the two yarn components, which are not located in the same position on the partially completed package, must then be searched for and picked up. This searching alone causes considerable problems. There is also the additional problem that in cases where as little as a difference of one package winding exists between the end of the two yarn components, i.e., one yarn component is longer by a corresponding package circumference length, it will no longer be possible to withdraw the two yarn components together and have them available for a piecing process. The searching and withdrawing therefore represents a problem even for manual piecing, but an automatic piecing machine would encounter problems which can hardly be solved.
An object of the invention is to provide a process and an arrangement by means of which it can be very reliably prevented that a single yarn is wound into the package by itself.
This object is achieved according to preferred embodiments of the invention in that, when one yarn component breaks, the cutting is carried out in such a manner that the lengths of both yarn components are at least approximately the same.
This results in that only one double yarn is located on the partially completed package so that the end of which, i.e., the ends of both yarn components, can be found and withdrawn in a relatively simple manner.
In a development of especially preferred embodiments of the invention, it is provided that, when one yarn component breaks, both yarn components, moving ahead of the breaking point in conveying direction, are cut simultaneously at the same distance from the partially completed package. As a result, it is achieved that both yarn components are still cut at the same point and at the same distance from teh partially completed package when only one yarn component breaks, so that the ends of both yarn components and thus of the double yarn will also be located at the same point of the partially completed package.
In a further development of the invention, it is provided that, when one yarn component breaks, the still existing double yarn is cut which is downstream of the breaking point of this yarn component in the travel direction of the yarn. This permits the use of only one cutting device.
In another solution according to the invention, which, under certain circumstances, may be used together with the above described solution, it is provided that the partially completed package is stopped before the broken end has moved onto same if one yarn component breaks. It will then be possible to find the ends of both yarn components and to withdraw the double yarn for a piecing process, even when these ends have different lengths.
In a further development of preferred embodiments of the invention, for the same purpose, in the case of an arrangement for producing packages which are used as feeding packages for twisting, onto which the two prestrengthened yarn components are wound side-by-side as a double yarn, having two drafting units arranged next to one another, having false-twisting devices which follow, having withdrawal devices, having devices for the guiding-together of the yarn components and for the winding of the yarn components onto a spool, and having devices which, when one yarn component breaks, cut the other yarn component, one or two cutting devices are provided which are connected behind yarn guards in the travel direction of the yarn and are controlled by the yarn guards in such a manner that the broken yarn component and the other yarn component have approximately the same length.
In this last mentioned development, it is advantageous for the yarn guards to be arranged directly behind the false-twisting devices. As a result, it becomes possible to detect a breakage relatively early in the course of the yarn and to react to it. In an expedient development, a joint cutting device is provided which is arranged in the course of both yarn components. As a result, it becomes possible to cut the two yarn components of the yarn structure, which is then still moving along as a double yarn, so that they definitely have the same length.
In order to have as much time as possible for a reaction, it is advantageous for the cutting device to be arranged directly in front of the spool forming the package. However, in this case, the fact must be taken into account that the yarn carries out a traverse motion in this area. So that no traverse motion has to be taken into account or at most one which is signficantly smaller, it may be provided in another solution of the invention that the cutting device is arranged in the area of a stationary yarn guiding element of the double yarn.
In a further development of preferred embodiments of the invention, a suction device for the cut-off pieces of the yarn components is assigned to the cutting device. The unbroken yarn component can enter into this suction device after the cutting so that, for a piecing operation, only the broken yarn component must be entered into the false-twisting device.
In another solution of the invention, it is provided that devices for the immediate stopping of the partially completed package are assigned to the devices for the winding-up of the double yarn, these devices for the immediate stopping of the partially completed package being controlled by two yarn guards which are each assigned to one of the yarn components. In this case, under certain circumstances, the unbroken yarn component may not have to be cut and must only be sucked off by means of the suction device for just so long until a piecing process for the broken yarn component is carried out.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.